Coatings for welding electrodes



Patented Aug. 3, 1937 i 2,089,101

UNITED STATES PATENT OFFICE COATINGS FOB WELDING HECTBODES Albert Roux, Enshlen. France, assignor to lAir Liqulde, Soclete Anonyme pour lEtude ct lExploltation des Procedes Georges Claude, Paris, France a No Drawing. Application May 18, 1934, Serlal No. 726,305. In Germany November 2, 1933 scum. (cl. 219- 8) This invention relates to coatings for arc weldcombustion of the hydrocellulose or oxycellulose, ing electrodes, such coatings yielding by their debut this result could be obtained independently of composition by the heat of the are or by their the adhesive bath by the addition of other subcombustion gases which protect from the instances, boric acid, kaolin i'orinstance, which act i fluences oi the surrounding atmosphere the metal as the proof materials. 5 at the place of the welding and the metaloi the Of course, ii necessary; there can be added to electrode when the electrode is made of metal. the paste the usual substances, fem-manganese,

According to the present invention, it has ,tale for instance, which add by the formation oi been ascertained that for such coatings use could slag their action to the action of the protecting 10 be made 01' cellulosic compounds which present gases or whichintroduce special elements into the m themselves under the form of an impalpable deposited metal. powder, the hydrocelluloses and oxycelluloses, and I claim: which are employed in admixture withone or more 1. A coating for arc welding electrodes which convenient binding materials in order to form a comprises an ingredient evolving in the are a prohomogeneous paste into which it is only necestective gaseous atmosphere and constituted by a sary, for obtaining the coated electrode, to dip degradation product of cellulose resulting as a the electroderod which is made of metal or of powder -from such action of chemical agents carbon; the coated rod is then dried or evaporated upon cellulose that avoids any substantial subto cause the paste to become solidand to adhere stitution of a group of atoms of the said -chemto the welding rod. The hvdrocellulose and the ical agents for the hydroxyl radical of the 20 oxycellulose are the known products of degradacellulose, and a binding material for holding said tion of cellulose by chemical agents. The hyingredient around the length oi the core of the drocellulose results from the attack of cellulose in electrode. the heat by mineral. acids, such as oxygenated 2. A coating for arc welding electrodes which acids or halogen acids: the oxycellulose results comprises an ingredient evolving in .the. are a 25 from the attack of the cellulose by oxidizing protective gaseous atmosphere and constituted agents, such as hvpochlorlte of calcium or perby a fibrous material resulting trom such action manganate of potassium. The results thus obof chemical agents upon cellulose that avoids any tained in the welding operation are at least equal substantial substitution of a group of atoms of 80 to those obtained with the coatings which comthe said chemical agents for the hydroxyl radprise cellulosic material. When this material is ical'oi the cellulose and a binding agent for said used under the form of yarns or' cords, it is necfibrous material, the fibres of said material being essary to wind it round the welding rod thus sufllciently short to allow this material to form necessitating-a relativelycostlyoperation-which is -wlth the said binding agent a homogeneous paste 85 avoided by the present invention; when-the celluremaining homogeneous along the welding rod.

losic material is used under a powder form, pracatter dipping said rod in said paste. tically sawdust, this powder swells under the 3. A coating for arc welding electrodes which action of the binding material which it is necescomprises an ingredient evolving in the are asary to add and does not permit to make a coating protective gaseous atmosphere and constituted by 40 of a thickness suiliciently constant for the comhydrocellulose. and a binding material 10: hold- 49 bustlon of the coating to proceed regularly across ing said ingredient around the length 01' the core the whole transversal section of the electrode. of the electrode. The materials'used according to the present "4'. A coating for arc welding electrodes which invention which are easily formed into a paste do comprises an ingredient evolving in the are a not have this drawback, provided that care is protective gaseous atmosphere and constituted by 45 taken that the filaments which enter their conoqcellulose, and a binding material for holding stitutionare suillciently short as can be ascersaid ingredient around the length of the core of tained by the microscope. the electrode. In order to use the hydrocelluloses and oxy- 5. A coating for arc welding electrodes which 50 celluloses, they are'incorporated into an adhesive comprises osycellulose. a 50 bath, preferably an immune silicate. The last ALBERT Rouxmaterial has together the eflect or retarding the 

